Each quarter, Hugh Howey and David the Data Guy crawl the Amazon.com website to gather data on Amazon Kindle eBook sales to determine how much money authors, publishers, and Amazon earn from daily eBook sales.
This quarter, they've also managed to gather data for print and audio book sales.
In one day in January 2016, Amazon.com customers purchased about 909,000 Kindle eBooks and downloaded the equivalent of 155,000 Kindle eBooks as Kindle Unlimited borrows, spending about $5,755,000 a day, which earns authors about $1,756,000 a day. In one year at this rate, consumers will spend $2.1 billion, and authors will earn about $641 million.
Of particular note, Hugh and Data Guy have taken nearly a million data points to calibrate the sales rank to daily unit sales. By looking at the chart below, you can see how many sales it takes to reach a rank and to maintain that rank.
For example, if your Kindle eBook were sitting at the 600,000 rank because it hadn't sold any copies in a few days and you ran a 99 cent promotion and sold 24 eBook copies, you can expect to reach the rank of about 10,000. If your eBook then sold 12 copies each day for the next several days, it would maintain a rank of about 10,000.
Thank you, Hugh and Data Guy, for doing all the hard work to bring us all this info!